This same distinction between what can be shewn by the language but not said, explains the difficulty that is
felt about types – e.g. as to the difference ¤ between things, facts, properties, relations. That || M is a thing can't be said: it is nonsense: but something is shewn by the symbol M. In the same way that a proposition is a subject-predicate proposition can't be said: but it is shewn by the symbol.
     :. a theory of types is impossible. It tries to say something about the types, when you can only talk about the symbols. But what you say about the symbols is not that this symbol has that type, which would be nonsense for the same reason: but you say simply This is the symbol, to prevent a misunderstanding. E.g. In „aARbB, R is not a symbol, but that R is between one name & another symbolises. Here we have not said this symbol is not of this type but of that, but only: This symbolises & not that. This seems again to make the same mistake, because ‘symbolises’ is ‘typically ambiguous’. The true analysis is: R is no proper name, &, that R stands between a & b (expresses a relation). Here are 2 propositions of different type, connected by ‘and’.
     It is obvious that, e.g. with a subject-predicate proposition, if it has any sense at all, you see the form, as soon as you understand the proposition, in spite of not knowing whether it is true or false. Even if there were propositions of the form ‘M is a thing’
they would be superfluous (tautologous) because what this tries to say is something which is already seen when you see M.
     In the above expression ‘aRb’, we were talking only of this particular R, whereas what we want to do is to talk of all similar symbols. We have to say: in any symbol of this form what corresponds to R is not a proper name, & the fact that … expresses a relation. This is what is sought to be expressed by the nonsensical assertion: Symbols like this are of a certain type. This you can't say, because in order to say it you must first know what the symbol is: & in knowing this you see the types, & therefore also the types of what is symbolised. I.e. in knowing what symbolises, you know all that is to be known; you can't say anything about the symbol.
     For instance: Consider the 2 propositions (1) “What symbolises here is a thing”, (2) “What symbolises here is a relational fact (or relation || = relation)”. These are nonsensical for 2 reasons: (a) because they mention ‘thing’ & ‘relation’ (b) because they mention them in propositions of the same form. The 2 propositions must be expressed in entirely different forms, if properly analysed; & neither the word ‘thing’ nor ‘relation’ must occur.
     Now we shall see how properly to analyse propositions in which ‘thing’, ‘relation’, etc. occur.